Curd, also known as bean curd milk, moldy tofu, etc., it is a microbial fermentation of soy products. It is a microbiologically fermented soybean product with a delicate texture, a delicious aroma and flavor, and is rich in a variety of trace elements needed by the human body, making it an indispensable accompaniment to meals.

Curd has a history of more than a thousand years and is one of the unique fermented products in China. As early as the fifth century A.D., the Northern Wei Dynasty on the ancient books have "dry tofu with salt ripening for the curd" said. In the "Materia Medica Gleanings", it is written: "Tofu is also known as beans milk, tofu marinated in wine lees or sauce system, taste salty and sweet." In the Qing Dynasty, Li Huanan's "Waking Garden Record" has already described in detail the production method of bean curd milk. The famous Shaoxing Bean Curd was exported to Southeast Asian countries more than 400 years ago during the Jiajing period of the Ming Dynasty, and its reputation was second only to that of Shaoxing Wine. 1910, it was awarded a gold medal at the exhibition of the Nanyang Persuasive Society, and in 1915 it was awarded a certificate of merit at the Panama-Pacific Exposition in the United States. In 1915, in the United States organized the "Panama Pacific Universal Exposition" and won the award. At present, China's curd has been exported to Southeast Asia, Japan and the United States, Europe and other countries and regions.

Curd is usually divided into three categories: green square, red square and white square. Among them, stinky tofu belongs to the "green side"; "big block", "red hot", "rose" and other sauce curd belongs to the "red side"; "red side" belongs to the "red side". Red"; "sweet and spicy", "osmanthus", "five spices", etc. belong to "white". White curd". White curd is produced without adding red curd pigment to keep its original color; curd billet with red curd pigment is red curd; green curd refers to stinky curd, also known as green square, which is added with bitter syrup water and brine during the pickling process, so it is soybean green in color. The fermentation process of stinky curd is more thorough than other varieties, so it is richer in amino acids. In particular, it contains more alanine and esters, which makes people feel a special sweet and ester flavor when eating stinky curd milk. However, due to the thorough fermentation of this kind of curd, resulting in the fermentation of a part of the protein sulfur amino acid and amino acid free out, resulting in obvious hydrogen sulfide odor and ammonia odor, so that people can smell from afar a stinky curd unique odor. There are varieties of fermented bean curd with the addition of bad rice known as bad party, the addition of yellow wine known as drunken party, as well as the addition of sesame seeds, roses, shrimp seeds, sesame oil and other colorful fermented bean curd. Jiangsu and Zhejiang, such as Shaoxing, Ningbo, Shanghai, Nanjing and other places in the curd to delicate and soft, fresh taste, slightly sweet known; and Dayi County, Sichuan Tangchang curd Sichuan flavor, spicy, crispy, tender and no dregs of the long; in addition to Chengdu, Sichuan, Suining, Meishan and other places produced by the cabbage tofu milk is also very distinctive, each piece of curd wrapped in cabbage leaves, the taste of fresh and spicy and palatable; Henan Tuo-cheng of the pasty curd is even more mellow, thick, delicious. It is thick and delicious.

Curd is usually used as a delicious side dishes, in addition to cooking can also be used as a seasoning, to make a variety of delicious dishes. Such as curd steamed bacon, curd steamed eggs, curd stewed carp, curd stewed tofu, curd bad intestines and so on. For example, the flavorful and fresh curd meat is made by browning the skin of the whole piece of meat on the fire and scraping off the burnt part in water. In a casserole dish the meat is cooked until half-crisp, then removed, and a knife is used to cut y into the skin so that it becomes a number of small pieces but is not cut. With a few blocks of red bean curd milk, put more marinade crushed with some yellow wine to mix well coated in meat, and then put into the casserole with onions and ginger and the original soup to cook the meat, slowly burned over a low fire and add rock sugar, to be thickened and thick juice can be. This meat is fat and not greasy, fragrant, appetizing.

Currently all over China have the production of curd, although they are due to the size of different ingredients, different varieties of names, but the principle of production is mostly the same. First of all, the soybean made of tofu, and then billet paddle into small pieces, placed in a wooden box can be connected to the strong protease activity of the root mold or trichoderma strains, and then into the fermentation and pickle billet period. Finally, according to the requirements of different varieties of red enzyme, yeast, mold, etc. for sealed storage. The unique flavor of curd is formed during fermentation and storage. During this period, microorganisms secrete a variety of enzymes, prompting the protein in the tofu blank to decompose into amino acids with high nutritional value and some flavor substances. Some of the amino acids have a certain freshness in themselves, and the fermentation process of curd also encourages the starch in the tofu blank to be converted into alcohol and organic acids, while there are also auxiliary materials in the wine and spices are also involved in the role of the *** with the generation of esters with flavor and other flavor components, which constitutes the unique flavor of the curd. Curd fermentation in the production process, protease and bacteria attached to the skin slowly penetrate into the interior of the tofu billet, and gradually break down the proteins, about three months to six months of time, fluffy and delicate curd is ready, the taste has become a delicate texture, fresh and tasty.

With the improvement of people's living standard and the development of national economy, people's demand for the quality of curd is getting higher and higher. Curd is developing towards low-salt, nutrition, convenience, series and other finishing aspects. We have reason to believe that curd as a national specialty will be more development.